Ets is a superfamily of genes and its members (ets-1, ets-2, ERG, ELK, PU.1) share amino acid homology with v-ets oncogenes of the E26 virus. The ETS1 and ETS2 genes have been involved in translocations associated with leukemias and lymphomas. The ETS2 gene is located on chromosome 2lq22, suggesting that it may be one of several genes whose amplification is associated with Down's syndrome. Recently, we have demonstrated that the ets-1 gene is autoregulated and the overexpression of Ets-1 and Ets-2 proto-oncogenes transforms mouse fibroblasts and induces tumors in nude mice. The members of the ets family of proteins are transcriptional activators and induce transcription via a purine-rich consensus sequence (AGGAA). We have been interested in studying the role of DNA binding activity of the ets proteins in cell proliferation and transformation; to address that aspect we expressed the ets proteins in the in vitro expression system in E. coli and insect cells. Similar to the ets-I product, the recombinant ets-2 protein shows binding activity with the purine-rich oligonucleotides derived from MSV-LTR and the PEA3 enhancer element.